Island



(No Model.)

W. H. SAWYER. ELECTRIG CABLE.

No. 473,351. Patented Apr. 19, 1892.

UNITED STATES PATENT OFFICE.

WILLIAM H. SAlVYER, OF PROVIDENCE, RIIODE ISLAND, ASSIGNOR TO THE AMERICAN ELECTRICAL VORKS, OF SAME PLACE.

ELECTRIC CABLE.

SPECIFICATION forming part Of Letters Patent No. 473,351, dated April 19, 1892.

Application filed October 27, 1891. Serial No. 410,011. (No model.)

T or/ZZ whom t may concern: Similar letters ot reference indicate like 55 Be itknown that I, XVILLIAM H. SAWYER, a parts in both iignres of the drawings.

citizen of the United States, and a resident ot In carrying out my invention the two insu- Providence, in the county of Providence and lated wires or conductors a forming one me- State ot Rhode Island, have invented new and tallic circuit are coiled spirally together to useful Improvements in Electric Cables; and provide a central fieXible tube or core hav- 6o I do hereby declare the following to be a full, ing a central air-space extending throughout clear, and exact description of said invention, the body of the saine. Upon the core or founreference being had to the accompanying dation thus provided are superimposed the io drawings, and to the letters of reference insulated wires of one or more metallic cirmarked thereon, which form a part of this cuits, which is accomplished byinterbraiding 65 specification. said Wires with a suitable fibrous material It is well known that when the wires ot' a tubularly around said flexible core or founda- .metallic circuit are kept equidistant from any tion, the wires of the superimposed series bedisturbing electrical influence, or when such ing interbraided spirally in a reverse direcwircs are not running parallel with others, totion to the wires of the coils composing` the 7C gether with the greatest amount of separailexible tube or core and all of the wires betion, the best results are obtained. ing` located at an approximately equidistance The object of my present invention is to and insulated from each other not onlyby the 2o provide an electric cable which is especially interbraided fibrous material, but also by air designed for telephone and telegraph service containedin theinterstices of the same, there- 75 and wherein the Wires of each metallic cirby producing' a cable wherein all the wires cuit are maintained at approximate equidisare of low static. capacity and high insulatances, thereby avoiding parallelism, and tion. A suitable number of sections formed wherein the greatest separation of the wires as above described are then grouped toorconductorsinthe smallestspaces attained, gether and inclosed within a lead sheath or 8o perfect insulation provided,aud the construcother suitable covering to produce the comtion generally being such as to secure the lowplete cable.

est possible specific inductive capacity. Having thus described my invention, what 3o To the above ends my invention consists of I claim as new and useful, and desire to secure an electric cable of the character described by Letters Patent, is 85 wherein the central core or foundation is coml. An electric cable composed of a liexible posed of the insulated Wires of one metallic tube or core formed of the two wires of a mecircuit being wound or twisted spirally totallic circuit coiled spirally together and the gether to form a flexible tube having a cenwires of one or more metallic circuits intertral airspace throughout the same,and upon braided with fibrous material upon said tlexio0 said tube or core are superimposed the wires ble tube or core, substantially as specified. of one or more metallic circuits, which are 2. In an electric cable, the combination of spirally interbraided or woven with suitable anumber ot' sections, each composed of a fieni- 4@ fibrous material thereon, the wires ot each ble tube or core formed of two wires ot a memetallic circuit being approximatelyequidistallic circuit coiled spirally together, a suc- 95 tant and the interbraided superimposed wires cessive series of metallic circuits interbraided being wound or coiled in a reverse direction with fibrous material upon said tube or core,

to those ot' said central tube or core. and an inclosing sheath or other suitable cov My invention consists, further,in grouping ering, substantially as specified.

a number ot' sections formed as above de- In testimonywhereofIatfixmy signaturcin IOO scribed into a cable and inclosing the same presence of two subscribing witnesses. in a lead sheath or other suitable covering, all

as will be hereinafter fully described, and VILLIAM H. SAXVYER. [L s] 5o specifically designated in the claims. I

In the accompanying drawings, Figure l Vv'vitnesses: represents a perspective view of one of the GILMAN E. J OPP, sections of the cable, and Fig. 2 a transverse CHAs. R. REMINGTON, Jr.,

section of the completed cable. 

